Objective: To observe the analgesic effect of Tuina by pressing and kneading the Huantiao (GB30) acupoint on rats with chronic constriction injury (CCI) and to explore the analgesic mechanism of Tuina on sciatica rats.
Methods: Thirty-two SPF male SD rats weighing 180 to 220 g were randomly divided into fore groups:blank group (without any treatment), sham group (only exposed without sciatic nerve ligating), model group (sciatic nerve ligating) and Tuina group (manual intervention after lsciatic nerve ligating). The CCI model was prepared by ligating the right sciatic nerve of the rats, on the third day of modeling, the rats in the Tuina group were given pressing and kneading the Huantiao (GB30) point for 14 days, and the changes of paw withdrawal threshold(PWT), paw withdrawal latency(PWL) were measured before and on the 1st, 3rd, 7th, 10th, 14th and 17th days after modeling. The changes of sciatic functional index(SFI) were measured before and on the 1st and 17th day after modeling. The morphological changes of the sciatic nerve were observed by hematoxylin-eosin(HE) staining;and the differences in NF-κB protein expression in the right dorsal horn of the spinal cord of rats were detected.
Results: Following modeling, there was no significant difference in PWT, PWL and SFI between the blank group and the sham group (P>0.05), but the PWT, PWL and SFI of the model group and the Tuina group decreased significantly (P<0.01). After manual intervention, the pain threshold of rats in Tuina group increased. On the 8th day of manual intervention (the 10th day after modeling), PWT in Tuina group increased significantly compared with that in model group (P<0.01). On the 5th day of manual intervention (the 7th day after modeling), the PWL of the massage group was significantly higher than that of the model group (P<0.01). The pain threshold of rats in Tuina group continued to rise with the continuous manipulation intervention. After 14 days of manipulative intervention, the sciatic nerve function index of rats in the Tuina group increased significantly(P<0.01). Compared with the blank group and sham group, the myelinated nerve fibers of sciatic nerve in the model group were disordered and the density of axons and myelin sheath was uneven. Compared with the model group, the nerve fibers of rats in the Tuina group were gradually continuous and the axons and myelin sheath were more uniform than those in the model group. Compared with the blank group and sham group, the expression of NF-κB protein in the right spinal dorsal horn of the model group was significantly increased(P<0.01). Compared with the model group, the expression of NF-κB protein in the right spinal dorsal horn of rats in Tuina group decreased significantly(P<0.01).
Conclusion: Pressing and kneading the Huantiao (GB30) point restores nerve fiber alignment;and improves the PWT、PWL and SFI in the CCI model by decreasing NF-κB p65 protein expression in the spinal dorsal horn. There fore, Tuina demmstrates an analgesic effect and improves the gait of rats with sciatica.
Keywords: NF-κB p65 protein; Pressing and kneading method; Sciatica; Spinal dorsal horn.